Electrical heating device.



P. J. HOLMES. ELECTRICAL HEATING DEVICE'.

May `.21,` 1912,' 2 SHEETS-SHEET 12.1

v lAPPLICATIONFILED JAN. 4, 1909.

1 ,027,337. Patented E .E E i..

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P. J. HOLMES. ELECTRICAL HEATING DEVICE.

AAPPLICATION' FILED JAN. 4, 1909.

Patented May l21, 1912'v 2 SHEETS-SHEET 2.

l Waarna@ [UNITED STATES "PATENT, OFFICE.v

FRANK J. HOLMES, or CHICAGO, ILLINOIS, ASSIGNOH To VULCAN ELECTRIC `II'imi'T'I'Nor COMPANY, or CHICAGO, ILLINOIS, A CORPORATION or ILLINOIS.

ELECTRICAL HEATING DEVICE.

" Patenteaivray 21,1912.

Application filed January 4, 1909. Serial No. 470,692.

To all 'whom it may concern:

Be it known that I, Fir-INH J. HOLMES, a citizen of the' United Sta-tes, residing at Chicago, in the county of Cookv andbtate of Illinoisl have invented' certain newl and useful Improvements in Electrical Heating Devices` of which the following is a full, Clear, concise` and exact description, reference being had Y to the accompanying drawings, forming a part of this specification.

My invention relates to electrical heating devices, particularly .to *su'ch devices vfor heating soldering tips, branding tips and so on, theinvention*contemplating novel and improved 'construction of the Various parts, to produce a iiioi'e durable and more eiiicient device of this class.

As one feature of my invention, I inclose all the active parts in a sealed, airtight case' or frame, this being a very important and desirable requirement, particularly in soldering irons.V yFrequently the user of a .solvdering iron' or other heating device .will

' V burn objects on which it is laid. This prac.-

plunge the device in Water to quickly cool it,` so that it can be put away for use and not tice is very detrimental rparticularly to unsealed electric soldering irons. lVhensuch aiiironis heated, the air Withinv the casing expands and is partly expelled, and if the iron is then plunged into water .the air contracts and causes the Water tobe sucked in. 1When current is again 'passedthrough the windings, a burn -out is liable to occ-ur. The consequence is that new windings must be very frequently inserted "and other repairs frequently made. By having the vcase airtight., the iron can be pluri ed in water Without moisture getting into tlg ing fiux and theoxygen and moisture of the 1 My invention comprises a number of other features ofconstruction useful in electric heating devices.

These Will appear in the following detailed description of van electric' soldering iron. I

In the drawings accompanying th'isidei scriptiou, Figure l is au elevation View of i parts, this' outerY sheath 8 of mica Serving the soldering iron; Fig. '2 is a diametrical y e casiiigand the windings and circuits will be protected,. .thus greatly prolonging the life of the iron'.

moved; Fig. 3 is an enlarged View of the terminal member; Fig. t isa sectional Viewv taken on line 4 4, of Fig. 3; Fig. 5 is an enlarged elevation View of a Spool insulator which I employ; Fig. 6 is an end view of said insulator; Fig. 7. is an elevation view of the spool insulator showing the Apreferable arrangement of terminal conductors therein; Fig. 8is a1i end vlew from the left of Fig. 7; Fig. 9 is an enlarged sectional view of the en d section of the insulating sleeve' which protects the conductors' betiveent-he insulating spool and the terminalmember; Fig. 10 is an enlarged View of the tip end of the soldering iron, .showing the manner of Sealing this end; Fig. 11 is an enlarged view'lof the tip end'after sealingand after the threaded scket hasfbeen c ut out for receiving the tip; and Fig. 12

shows the same arrangement as Fig. 11,

with the soldering tfip inserted. l

Thenietallic frame or inclosing shell for the iron comprises the tubular section 1, which forms the cylindrical Wall for the heat producing member, and the tubular section 2.

l may be of larger diameter, as shown. The

end 3 of the extension 2 extends a short dis# Depending-upon the size and-` -capacity of the-1ron, these tubular sections tancev into end 4 of section. 1, these ends being securely brazed together. A' ring 5,

then slipped over the ring also with a tight fit, so that the tubular parts will hold themselves relatively rigid; Instead of inserting' a ringLI may spin the tube down to fit in the end of the core. An annular cup 6 is thereby formed, which is filled with brazing. i alloy and suitable flux applied.' When heated, the alloy firmly brazes together the ends 3 and 4,'and the collar 5 `is also securelybrazed to these ends, thus forming an absolutely airtight joint at this point.

The heating member for the iron'coinprises the core 7, preferably of copper',- surrounded by the heat producing Winding 8.

'This' winding is of a Suitable number' of 'l turns, and is preferably insulated from the I core by mica, mica 8 being also Wound about the outside of the Winding, so that the Winding is protect-ed from adj acent. metallic core. This core is wound before insertion in its casing 1. To take care ,of the termirnals of the-winding, a spool insulator of and 13 forming between them the channel 14. There are four holes or passageways,

15, 16, 17 and 18, through the end 11 parallel with the'axis, these holes terminating in the plane of the, channel 14, and to meetthese,passagewaysythere are other passagei ways 19, 20, 21 and 22 in the plane of the channel 14. The coil terminals 23 and 24 pass downwardly through Itwo of the openings in channel 14, and thence through two of the openings. in end 11, from which the terminals extend. The other end of the core is drilled to form the pocket 25, which has' the end section 26 of slightly larger diameter, and the beveled inner edge 27. After the core is wound and the terminals inserted through the spool insulator', it is slipped into the section 1 with the terminals' extending into and through the section 2, the end 11 of the insulator spool engaging in the end 3 of the tubular section 2. The tip end of the tubular section is now sealed. For this purpose a ring 28, preferablycf steel, is inserted between the end of section 1 and the end of the core preferably with a tight fit. This ring could alsobe slipped on the core before the core ,is inserted in the' section 1. In the first place, this ring together with the end 11 of the spool which engages in the end of tubular section 2, supportsthe core structure in central position within the tubular section 1. In the second place, the ring 2S vforms the bottom for the annular cup 29 formed between the tip ends of the core and section 1. The tip end of section 1 is primarily longer, and when the c ore is inserted, projects quite a distance beyond the core end. In the annular cup 29 and in the pocket 25 brazing alloy is then` filled and flux material applied.`

When this tip end is heated, the ring 28 and the tip ends ofthecore and the casing 1 will be securely brazed together to form an absolutely airtight joint, thus hermetically sealing this end'of the core chamber. After brazing., the tip end is machined, the final arrangement being that shown in Fig. 11. In the first place, theextra end of the casing 1 is cut away and then the material in pocket 25 is drilled intoiand provided with threads 30, whose diameter is less than the original diameter of thepocket. The, entrance edge 31 is cut toa taper, and a small in, the tapering surfaces 34 and 31'come into snug engagement and the tip is thus rigidly held in place. This snug joint prevents the entrance of acids or other foreigncorrosive material to the threads. y If any foreign sub# stances should get bythe tapered surfaces, it would lodge in the chamber between the threads 30 and the base of the soldering tip, this chamber being formed by the section 32 and the space between part of the taper end 31 and the base of t-he soldering tip. The beveled edge of the tip engages only the outer part of the beveled surface 31. The looseness of the threads, will prevent the foreign substances from having any bind.- ing effect, and unequal expansions will also be taken care of by the loose thread arrangement. The result is that the soldering tip can always be readily removed. while at the same time it is held rigidly to the frame.

In other irons with which I am familiar, f

the corrosive substances which leak in between the soldering tip and the supporting frame will bind the tip to the frame. so that its removal is accomplished with difficulty.

The dimensions of the core windings and insulation are such that when the corestructure'is slipped into the casing section. there will be an annular air chamber 36'between the c"ore structure and casing 1'. This air chamber serves as an insulating medium to prevent theheat from the windings from radiating-to` the frame 1 and thus becoming dissipated and lost, the generated heat beingr concentrated and confined to the core, which is of copp'er, the heat flowing to the soldering tip which is in intimate Contact with the core end and which is also of high heat conductive material.

The coil lead wires which extend through the tubular section 2 terminate in connectors 37 and 38. These connectors are supported on a cylindrical terminal block 39 of fiber, rubber, or other suitable insulating material best shown in Figs. 3 and 4. Each of these connectors before application comv prises a tubular part 40 having the flange 41. In assembling, the connectors are slipped into one end of the openings 42 and 43 extending from the bases of slots or channels 44 and 45, and a spreading toolis then applied from the other end of the openings, and the ends 46 spread outwardly to secure the parts in place. The'connectors are' then tapped -for receiving the binding screws 47 and 48.` The terminal block has a reduced end 49 for fitting into the end ofl tubularA section 2, a pin 50, serving to hold the terminal member in place. Beforethe terminal block is inserted, however, an insulating and protecting sleeve 51 is slipped over the lead wires and V'into the section 2. This sleevemay be appliedover the wires before vthe core structure is applied inthe section 1. Lead wire extends through'passageway 52 in sleeve 5,1, and then through passageway 53 in the terminal block, its end being .soldered to the edge of connector 37, as best shown in Fig. 3. Lead wire 24 likewise extends through passageway 54 in sleeve 51 andA through opening 55 'in the' terminal block, its end being soldered to the contact member 38, asV shown in Fig. The conductors c for connecting the Winding with a source of electricity, are laid in the channels 44 and 45 of the terminal block,

' the ends of the conduct-ors being clamped to the connectors 37 andg38 by the screws 47 and 48, respectively.

56 through which the' conductors c pass and cross. this forming a means for preventing strain on the conductors from being communicated to the terminal members.

ln order to make the winding chamber air and water tight, the terminal end of tubular part 2 is sealed. This sealing may be accomplished by means of wax 57, or

otherA insulating compound, which is placedinto'the end of section 2 and about the'end 58 of sleeve 51, which is preferably of i'educed diameter. for sealingthisend is as follows` and is illustrated partly in Fig. 9,. The ends of the passageways through the sleevel are of Aenlarged diameter to form pockets 59 and 60. Aboutrthe lead wires a material such as asbestos is packed into the pockets. 59, '60, and also around the sleeve end 58V the temperature varies, and expansion and contraction occur, the wax 6l will follow and maintain the sealed conditions.

Before applying the wax. l preferably heat the iron to the greatest temperature which it is apt toreach in service. and this heating mav be accomplished b vattaching .is the the iron to an electrical circuit. iron yis heated. any moisture which may be At the .outer end' of the terminal block is a' transverse holev A preferable procedurei V"vs-tithin lthe casing isvdriven out and the 'greater part ofthe air is also` driven out. The waX 57 is then poured in, or placed in solidfand melted into place'by the heat of the iron. The iron is then allowed to cool.`

Upon cooling, the air tends to rush back -into the iron tog replace that driven out,

and the wax therefore is pneumatically pressed firmly into place and particularly in pockets 59 and 60 and in the space about the sleeve end 58. The wax having been put in under these conditions will therefore never be blown out of-yplaceowing to the' expansion of air within the casing partsz A After the wax is applied, the terminal block is secured to the end of section 2 and thewinding` leads soldered Ato t-lie connectors 37 and 38, as has already been eX- vplained. Any suitable form of handle may As shown, I have provided a cylindrical handle' 62, which has a center bore63 preferably be provided for the metallic frame.

of slightly larger diameter thanfthe tube 2 over which the handle is slipped, in order to allow for expansion and contraction. A. brass collar 64 is secured about the front end of the sleeve by pins 65, and the end of the collar has interior threads 66 for engaging the threaded sleeve 67which is securely brazed to the tube part 2. This sleeve partterminates in Aa head or stop liange 68 for receiving the end of the collar 64. The conductors c extend through andfrom the rear end of the handle for connection .in any' suitable manner with a source of current.-

As vshown in Fig. 2, the leads of the heat'.-

loo

producing winding continue through thev sleeve 51. The wire of these windings. however, is usually of small caliber, and might readily break during the assembling and sealing process, and would also generate heat when it is not required. Itl isv therefore vpreferable to have heavier leads connecting with the connectors and with the winding leads where they emerge from thel insulating spool. Figs. 7 and 8 show such an arrangement. The special leads 69 and?l 70 may be of a larger wire and of lower resistance than the wire on the core. The vend of lead 69vis, banchored to the insulating spool by passing in through opening 15 and out through passageway 20, then along the channel 14 and through passageways 19 and 17. Lead wire 23 of the winding is then passed through passageways 20 and 15, and is coiled about and brazed to lead 69. In

a similar manner, lead 24 passes through passageways 18 and. 21.' channel 14 and passageways 22 and 16. terminal 24 passing through passageways 21 and 18 and is coiled aboutl and brazed to lead 70. 'When the sleeve 51 is now applied. the coiled ends of' the terminals 23 and 24 will be received by the pockets 71 and 72 formed by the enlargedl inner ends of the passageways ,ends of the leads so as to prevent any strains on the, winding Wires. 'v

The soldering tip for an iron of this construction should be of material which t has high heatv conductivity, or should have lsome element which possesses high heatfconductivity. Other tips, such as branding or leather embossing tips, could be appliedto the heating device, to lbe heated, and these may be of any construction to cause the heat to be condiictively'le'd to the place where `the heat is required.

Thereare many changes in detail construction and arrangement which could be made without departing from my invention. I do not, therefore, limit myself to the/precise arrangement which I have shown.- I think it is broadly new with me to produce a heating device of the class described, in whichv the active parts are sealed, this enabling the heating device to be subjected to all the uses and abuses in the various trades in which it is used. l l

I desire to protect the following claims by United States Letters Patent:

l. In a lieatingdevice of the class de-` scribed, the combination of heat producing means, a highly conductive member` associated with the heat producing means, a tip or heat applying member for receiving the heat from the conduct-ive member, athreaded opening in said conductive member, an extcnsionfroin the tip or heat applying member threaded-to loosely tit the threads in the conductive member, and a tapered seat' on the conductive member, said tip or heat applying member having a tapered edge for engaging the seat when-the tip is screwed to the conductive member. v

2. `In a device of the class described.' the combinationof a copper core. an electrical heat producing winding surrounding said core, a threaded pocket in one end of said core, a tip having a. threaded extension of less diameter. than said threaded pocket for engaging with the threads of said pocket to secure the-tip to the core, and a tapered seat at the edge of the `pocket, said tip having a tapered edge for engaging said seat when' the threadedextension is screwed into the pocket. 4

3. Ina heating device of" the class described7 the combination of a tubular inclosing frame orshell forming chamber at one end, a core in said chamber. a heat producing winding surrounding. said core, a terminal member engaging the other end of said shell, conductors connecting the winding with said terminal member. said conductors passing through the shell and being insulated therefrom, means at the end of the core whereby a tip or4 heat applying member may be secured to the core to conduct-ively receive heat therefrom, means for connecting the "end of the core and. shell together to seal said end of the shell, and sealing means at the other end of the shell, said shell. being thereby hermetically sealed.

et. In a device of the class described, the

combination of a metallic inclosing frame orl shell, a core of highly conductive material in one end of said shell, a heat'producing winding surrounding said core, a threaded opening in the end of said core for receiving the threaded end of a tip or. heat applying member, a terminal member at the other end of the shell, conductors passing through the shell and connecting the winding termiiials With the terminal member, the end of.

the conductive core and the metallic shell being brazed together to hermetically seal this end of the shell, and sealingvvax applied to seal the other end of the/shell.'

v 5. In a heating device of the. class described, the combination of ay core ofgood heat conductive` material, a heat producing winding surrounding said core, a metallic inclosing shell about said core and winding, a pocket in the end of said core, sealing malterial for` connecting `together the' ends of "extension from said shell of less diameter than said shell, a. core in said tubular shell. a winding surrounding said core, a spacing ring between one end of the core and said shell, an insulating spoolengaging at onceiid in the oth'er end of said core and at its other end engaging in the tubular eXten-4 sion, said spacing ring and spool servingto hold the core concentrically within the shell, openings through the spool for accommodating the terminalsof the winding, and a terminal member at the'end of the-tubular extension connected with the winding' `secured to the end of the core in intimate contact therewith to receive the heat there- :isc

from, a heat- PlOducing Winding urreimding the core, a' spool engaging Withitheothe'r end'of the core and extending into the' tubular extension, and y passageways through said memberfor accommodating the Winding terminals, said terminals extending lthrough the tubular extension to be connectedywith an external source of electricity. A 8. In a heating device of the class described, the combination of a tubular shell forming a chamber, a core in said shell of good heat conductive material, a lheat r0- ducing Winding'in said shell surroun ing the core,'means at the outer en d of said core whereby a tip or heat applying member may besecured to the core to be vin intimate cont-act therewith, a tubular extension from said shell, an insulating spool secured in the other end lof the core and extending into the tubularn extension, passageways through said spool for accommodating the Winding terminals, a terminal'member at the lend of said tubular extension, and leads extending from said terminal member through the tubular extension and anchored to the spool, the winding terminals after passage through .the vspool openings being electrically secured to the leads.

9. In a heating device of the -class described, the combination of heat producing -means, a highly conductivel member' associated with the heat producing means, tip or heat applying member for receiving the heat from the conductive member, a threaded recess in the heat conducting member,

and threads on said tip for fitting loosely in said threaded recess, there being a beveled bearing surface between the tip and said conductive member.

10. In a heating device of the class dethe combination of a tubular in closing'shell forming a chamber, a core in said chamber, a heat producing Winding surrounding said core, a terminal head engaging one end of said shell, conductors connecting thewinding with said terminal head, means at'the other end of the core for receiving the tip, and means for connecting the latter end of said core .and the'shell together to seal the end of the shell, and sealing means at the other end of the shell,

said shell being thereby hermetically sealed.

ll. In a heating device of the class vdescribed, the combination of an inclosing shell, a tubular extension from said shell of less diameter,-a core of heat conductive material in said shell, means at the end of said core for receiving a tip, a heat producing Winding `surrounding the core, and a spool-engaging-the other end of the core and extending into the tubular' extension, theA winding terminals passing through said` spool.

l2. In a heating device of the-class described, the combination lof a heat produc?,

ing means, a highly conductivefmember associated With the heat producing means, and l a tip or heat applying member for receiving the heat from the conductive member, there being a threaded recess in the conducting.

member and threads on said tip/for fitting loosely in said threaded recess and there be# ing an oblique jamming surface between the 'tip and said conductive member.

In Witness whereof, I hereunto subscribe my name this 29th day loi` December 1908.

' FRANK. J. HOLMES.

Witnesses:

CVHARLESJ. SCHMIDT,V FRANK J. THELEN.. 

